//------------------------------------------------------------------------------
//  <copyright file="CollisionChecking.cs" company="Microsoft Corporation">
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namespace Microsoft.Robotics.Collision
{
    using System;
    using System.Collections.Generic;

    using Microsoft.Robotics.Geometry;
    using Microsoft.Robotics.Numerics;

    /// <summary>
    /// Base class for a collision checker
    /// </summary>
    public abstract class CollisionChecking
    {
        /// <summary>
        /// The core method for a collision checker which evaluates the closeness between element groups in groups1 and groups2.
        /// It should return a number which quantifies how much the collision is.
        /// If the return value is positive, it is the shortest distance of between the geometry elements in groups1 and groups2.
        /// If the return value is negative, it is the deepest penetration between the geometry elements in groups1 and groups2.
        /// </summary>
        /// <param name="groups1">First list of element groups</param>
        /// <param name="groups2">Second list of element groups</param>
        /// <param name="distances">A double array with its cell distances[i][j] indicates the distances between element group i in groups1
        /// and element group j in groups2</param>
        /// <returns>A number that evaluates the collision.
        /// It should return a no-less-than-zero number which indicates the shortest distances between two element groups.
        /// It should return a negative number which indicates the penetration depth.</returns>
        public abstract double CheckCollision(List<GeometryElementGroup3D> groups1, List<GeometryElementGroup3D> groups2, out double[][] distances);
    }
}
